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Does snacking from a large bowl result in overeating?

It is often stated that the accumulation of excess body weight is a simple matter of energy intake exceeding energy expenditure. While this notion is certainly correct, it does not account for the myriad of factors that drive one to consume more calories than necessary.

Take for example the size of a bowl from which you eat your snacks.

Could this simple factor play a role in the number of calories you may consume?

Back in 2005, Wansink and Cheney performed a wonderfully simple study and found that when snacks are offered in a large bowl, people take 53% more food (146 extra calories) and eat 56% (142 calories) more than when offered the same amount of food but in a smaller bowl (roughly half the size of large bowl).

In the study, 40 graduate students were invited to attend a Super Bowl party (not sure why I was never involved in such “research” in my department). Right after they entered the party, the participants were led to 1 of 2 snack bars where they were offered snacks to consume during the game.

Both snack bars had the same amount of identical snacks (roasted nuts and pretzel/chip variety mix).

While the one buffet offered the snacks in 2 large bowls (4 L capacity) the other offered the same quantity of snacks in 2 medium bowls (2 L capacity).

Each participant served themselves on 10-inch plates, and had their plates weighed prior to joining the other participants in another room and watching the game.

One hour later, each participant filled out a survey and the amount of food they ingested was measured (difference between how much initially taken and how much was remaining).

A total of 5 of 40 participants did not take any snacks when offered. It is not reported whether these individuals were smuggling carrot sticks in their pockets. Regardless, they were swiftly and forcibly removed from the party. (Okay, that didn’t actually happen. The non-snacking weirdos were allowed to stay at the party and probably make the rest of the participants feel guilty.)

The effect of bowl size on caloric consumption was not influenced by body weight, hours since last meal, age, or education. However, gender did play a role; males were more susceptible to the influence of bowl size.

Take home message?

If you have friends coming over for a party, or you’re making snacks for yourself or your family, try the following: place the healthy snacks in large bowls and the unhealthy ones in small bowls. Theoretically, this would result in a greater consumption of healthy snacks and a limited consumption of unhealthy ones. Even better, you can do away with the unhealthy snacks altogether.

Thanks for the comment and for following, Ernesto! I agree about the cool research Wansink has done, and I had come across it on numerous occasions and made notes to myself to blog about the work, but kept forgetting. Very glad I finally remembered to bring it up. The bottomless soup bowls is also very cool. I hope to get around to that soon.

Having heard Wansink talk about this very study there’s another important piece to note.

Those very grad students were part of a class taught by Wansink himself on mindless eating cues.

Therefore the findings were despite the fact that the subjects were formally schooled in mindless eating suggesting that knowing about mindless eating cues isn’t in and of itself a defense and that like you stated, using smaller bowls and rejigging your environment is the way to go.

Thanks, Yoni. I had no idea about that extra layer to these findings. Very cool. In a sense, it also reminds me how many of us in the obesity, exercise, nutrition fields often do not practice what we preach. Your recent post on the food at the Obesity Society meeting is a perfect illustration of the cognitive dissonance many of us develop.

The fact that they were ‘schooled’ in mindless eating cues for probably a single semester can hardy be expected to outweigh, if they are anything like typical Americans, some twenty years of intensive indoctrination into mindless eating as a practice.

Do other primates behave this way (easy to check)? Do otherwise equivalent people (i.e. university-educated adults) who have not been exposed to advertising or similar training behave this way (not so easy to check)?

Absolutely I think their “schooling” matters, though not having read the paper in years I can’t recall if Wansink included his non-standard sample as a strength or a weakness or even a mention, but I’d argue it could be argued either way.

These were Wansink’s own students, currently taking in a class that explicitly details mindless eating cues, being invited by Wansink himself to a Superbowl party experiment being conducted by Wansink.

Either it strengthens his arguments because clearly they knew exactly what they were getting into and the average person would therefore be expected to mindless eat even more or perhaps, consciously or unconsciously, his pie-eyed enthusiastic students (Wansink’s an incredibly animated, motivating, exciting lecturer), wanted to prove Wansink’s theories to be true.